1. Surface quality requirements:
A. There must be no cracks on the end ring, fan blades and balance column.
B. The size and depth of the shrinkage hole on the surface of the end ring should be less than 20% of the height of the end ring, and the maximum should not be greater than 3mm. Only one spot on each end is allowed.
C. The missing blades and sharp corners should be less than 3mm.
2, size requirements:
A. Rotor core length tolerance. Iron core length L<160mm, allowable tolerance +2.0mm; iron core length L≥160mm, allowable tolerance +2.5mm.
B. Deflection of the outer circle of the end ring and the outer circle of the iron core. The core outer diameter Φ<100mm, the maximum deflection is not more than 1.0mm; the core outer diameter Φ<250mm, the maximum deflection is not more than 2.0mm; the core outer diameter is Φ250～400mm, the maximum deflection is not more than 3.0mm; the core outer diameter is Φ> 400mm, the maximum deflection is not more than 4.0mm.
C. Deflection of the end ring end facing the end face of the core: same as b.
D. The allowable deviation of the rotor slot inclination is ±1.0mm.
E. The oblique slot line on the outer surface of the rotor must be straight, and the wrong piece of the rotor should be less than 0.5mm when viewed from the oblique line of the slot.
3, internal quality requirements:
Check for defects such as broken bars, cracks, pores, porosity and shrinkage.